Help me with these questions please!

Use the profile illustrated for problem (1). assume that the layer of silty sand fill (sm) is placed over the entire site. estimate the thickness of the fill (h - in feet) that will cause the effective vertical stress at the center of the clay layer to increase by 517.5 pounds per square foot.

Name two kinds of practical electric pumps.

Wavelength of 125 meters is moving at a speed of 10 m/s. what is it's frequency?